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<html lang="en">
  <head>
    <meta charset="UTF-8" />
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    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .big-box {
        width: 200px;
        height: 200px;
        margin: 0 auto;
      }
      .size {
        font-size: 24px;
        margin: 20px 0;
      }
    </style>
  </head>
  <body>
    <div class="big-box">
      <div class="box">页面一</div>
      <div class="size">javascript能够做什么</div>
      <button class="btn">点击我！</button>
    </div>
  </body>
  <script src="./index.js"></script>
</html>
